Abstract: Four methods of ranking horses on reactivity were evaluated and compared: isolation from conspecifics, presentation of a static novel stimulus, traversing a novel stimulus in a runway (isolation, novel stimulus and runways tests, respectively) and assigning subjective emotionality scores. Forty horses performed each of the three tests daily on three different days in a switchback design where treatments were injection of a tranquilizer or vehicle. Horses were randomly assigned a daily test sequence, which was maintained throughout the study. In all tests, heart rates were recorded and behavior was videotaped. To be considered a valid test of reactivity, at least one heart rate and one behavioural measurement in the test had to show a significant difference due to tranquilization, and behavioural measures had to be displayed in at least 75% of the trials. In the runway test, no significant difference in heart rate values in tranquilized and non-tranquilized horses was found, and no behavioural attribute was displayed in more than 52% of the trials; therefore it was rejected as a valid test of reactivity. Both isolation and novel stimulus tests produced valid measurements. Mean heart rate was the most precise physiological measure for these tests, and walking and defecation frequency were the most precise behavioural measures for novel stimulus and isolation tests, respectively. Mean heart rates on the novel stimulus and isolation tests were correlated (rs=0.79, P<0.01) indicating that these tests produced similar rankings based on physiological responses. However, behavioural measures ranked horses differently (rs=0.27, P<0.10) on the tests. Rank correlations between mean heart rates and behavioural measures were higher in the novel stimulus (rs = 0.66, P<0.01) than the isolation test (rs = 0.55, P<0.01), indicating that the novel stimulus test ranked horses based on either physiological or behavioural responses more similarly than did the isolation test. Therefore, the novel stimulus test was considered the more accurate evaluation of reactivity. Subjective emotionality scores were correlated moderately with mean heart rates (rs > 0.33, P<0.01) from the novel stimulus and isolation tests and with walking scores (rs = 0.47, P<0.01) from the novel stimulus test. Assignment of subjective emotionality scores was not as accurate as the novel stimulus or isolation tests in ranking horses for reactivity. Using physiological data alone, combining physiological and behavioural measurements or using more than one behavioural measurement in reactivity tests may reflect the reactivity of the horse better than a single behavioural measurement.

Abstract: Cribbiting is a common stereotypy in domestic horses and is associated with stress and low fibre/high concentrate diets, which are known to cause gastric inflammation and ulceration. Recent studies indicate that antacid supplements can reduce both gastric inflammation and cribbiting. However, stereotypies are also associated with altered brain functions and these are thought to be responsible for emancipation. Emancipation refers to a process by which stereotypies become increasingly independent of the causal factors and may therefore persist with age, regardless of the conditions. Emancipation complicates therapy and points to the importance of prevention.
To further examine the relationship between gastric health and cribbiting and its relation to age at onset, we examined the effect of the proton-pump inhibitor omeprazole (GastroGard, Merial) on gastric inflammation/ulceration and on cribbiting in a double-blind placebo-controlled study. Thirty-one horses of different sex, breed and age were randomly allocated to treatment and placebo and divided into three groups depending on age: 0-5 years (n=11), 5-10 years (n=11) and >10 years (n=9), whereby age at onset of cribbiting was &#8804; 5 years for all horses. Treatment and placebo were administered orally by syringe once every day for 28 days by the horse owners. Treatment consisted of 4mg/kg omeprazole for the first four days and 1mg/kg for the following 24days.
Using scan sampling and behaviour sampling, general activity and the number of crib-bites were assessed in the home pens one day before and one day between day 21 and 28 of treatment. Observations were made for three hours each around morning and evening feeding times, respectively. Prior to pre-treatment observations and after post-treatment observations, the horses were transported to the clinic and endoscoped for signs of inflammation and ulceration in the oesophagus, the squamous area, the glandular area and the first part of the duodenum using a common scoring system (Andrews et al. 1999).
All 31 horses showed signs of gastric inflammation/ulceration which decreased significantly from a median score of 1,2 to 0,6 in the treatment group (Wilcoxon signed rank test, z=-3,186, p=0,001), while there was no change in the placebo group (z=-0,577, p=1.0). However, there was no significant difference in cribbiting before and after treatment, neither in the treatment group (z=-1,834, p=0,068), nor in the placebo group (z=-0,415, p=0,734). Moreover, there were no significant effects of age on gastric inflammation/ulceration (2-way ANOVA, F=1,112, p=0,345) or cribbiting (F=1,113, p=0,344).
These results contrast with the recent studies on the effects of antacids on gastric health and cribbiting. There are two possible explanations for this: First, cribbiting may become rapidly established and may thus have persisted even in the youngest age group. Second, omeprazole acts specifically by reducing gastric acid secretion into stomach, while antacids may also have an effect on the intestine. However, these results shed doubts on the hypothesis that cribbiting is caused by gastric inflammation/ulceration.

Abstract: When keeping horses in run-out sheds, feeding stalls are usually recommended for individual feeding; which allows equine typical simultaneous eating. However, automatic feeding devices for hay and concentrates are being increasingly used, and these do not allow simultaneous eating. This research aims to compare visiting frequency, stress situations, and the risk of injury, in the area of automatic feeding systems with those at feeding stalls. The studies were carried out at 10 stables with feeding stalls and at 11 with automatic feeding systems for hay and concentrates. These stables were otherwise similar regarding the keeping of the horses and the management of the facilities. Each group consisted of 8 to 21 horses, with 260 horses taking part in total. Every group was observed for 6 sessions, each of 4 hours. These 6 sessions together made 24 hours, a complete day.
Horses in stables with feeding stalls visited the feeding area (waiting area, the station, exit area) 45.5 ± 27.3 times on average in 24 hours, and in stables with automatic feeders for hay and concentrates, 93.1 ± 53.5 times. This difference was significant. Threatening behaviour, without risk of injury or with risk of injury, occurred significantly more frequently in stables with automatic feeders (9.6 ± 12.9 times and 4.2 ± 5.5 times respectively per 24 hours and horse) than in stables with feeding stalls (6.0 ± 10.4 times and 1.5 ± 3.3 times respectively per 24 hours and horse). The management of the stable, however, proved to have its most important influence on the behaviour of the horses.
Displacement activities were observed in stables with feeding stalls 0.3 ± 1.0 times per horse and 24 hours and in stables with automatic feeders for hay and concentrate 12.9 ± 23.3 times. Situations that could cause either stress or injuries to the horses occurred in stables with feeding stalls within 24 hours per horse only 3.7 ± 13.1 and 1.3 ± 4.8 times on average respectively. Such situations were to be seen in stables with automatic feeder 17.0 ± 33.4 and 8.6 ± 15.3 times respectively per horse and 24 hours – clearly more often.
We may therefore conclude that the more often the feeding area is visited, the more frequently threatening gestures without and with risk of injury occur. The same goes for the number of situations that may result in stress or injuries. Therefore to sum up it can be said that feeding in feedings stalls leads to less risk of stress and injuries compared with feeding by computer controlled systems. On the other hand, computer controlled systems have the advantage of stimulating the horses to move, which is very important for their health. While assessing this study it should be taken into account that there were very big individual differences between the horses. The result of the statistical evaluation was that the management of the stable has a decisive influence on the observed features. Therefore both feeding systems can be recommended, especially as the number of conflicts in the feeding area in all stables was relatively low and no injuries were observed in connection with the feeding.

Abstract: Historic overlap zones of wild equids were small in Africa but extensive for Przewalski`s horses and Asiatic wild asses in Asia. Currently the Great Gobi B Strictly Protected Area in SW Mongolia is the only place where sympatric, free-ranging populations of these equids occur. This provides an unique opportunity to examine the co-existence of these little studied species and test the hypothesis that Przewalski`s horses are primarily adapted to mesic steppe habitats, whereas Asiatic wild asses are adapted to arid desert steppes and semi-deserts.
We monitored 9 Przewalski`s horses and 7 wild asses with satellite telemetry and superimposed the data on a habitat map derived from remote sensing (LANDSAT TM & ETM+-data) and ground sample plots. We tested for habitat preferences comparing use and availability with a logistic regression mixed model approach. Individuals were treated as random factors. Factor variables were tested for significant differences in subsequent Tukey post-hoc tests. Przewalski`s horses had non-exclusive home ranges of 152-826 km² and heavily selected for the most productive riparian plant communities. Asiatic wild asses also had non-exclusive home ranges, but with 4,449-6,835 km² they were 10 times larger than those of Przewalski`s horses. Asiatic wild asses seem to use plant communities more or less relative to their availability. Our results provide evidence for two parallel resource selection strategies. Our findings indicate that the Gobi areas provide an edge, rather than an optimal habitat for Przewalski`s horses. This leaves only small and isolated pockets of suitable habitat for future re-introductions. Asiatic wild asses, on the other hand, need access to large tracts of land to cope with the unpredictable resource distribution of the Gobi. Thus, Asiatic wild ass conservation requires a large scale approach.

Abstract: The Humane Society United States (HSUS) has been partnering with several prominent researchers for over 20 years to assess the potential use of Porcine Zona Pellucida (PZP), a protein used as a fertility control vaccine for wild horses. Past studies on herds located on barrier islands of the eastern United States have demonstrated that PZP prevented pregnancies and was a valuable tool for population management. With the generous support of the Annenberg Foundation and in partnership with the Science and Conservation Center, Tufts University and The University of Toledo, HSUS is conducting a 5-year longitudinal study to assess the effectiveness of immunocontraception on over 600 wild horses in the western United States.
This project involves 2 herds of over 300 wild horses each located in Utah and Colorado. We began gathering pre treatment data in April 2008. Birth rates, band size, and individual horse identifications were recorded. In the winter of 2008/2009 both herds will be captured and all mares that are released will be treated with a 2-year-duration PZP vaccine. Both herds will be closely monitored for reproduction and behavior changes for 3 years. We will record the differences in reproductive success of treated and untreated (not captured) females.
HSUS is also seeking to develop refinements to the PZP vaccine and delivery technologies. HSUS is currently trying to improve the production of the PZP vaccine by producing it with techniques that are more efficient and less costly. Improving delivery methods for the 2 year drug is another goal of this research that may allow herd managers the flexibility of treating mares year round without having to capture it. HSUS also hopes to demonstrate that incorporating this new delivery method and proactively managing wild horse herds will assist in maintaining wild horse populations at a level that is sustainable and manageable.